One aspect of invention relates to a transceiver device.
In wireless communication, prior art antennas are implemented as independent passive components, i.e. as components provided separately from a chip, which are not integrated in such an electronic chip.
One application for antennas in wireless communication are the so called radio frequency identification tags (RFID tags). Radio frequency identification (RFID), the identification by radio transmission, is a method for being able to read and store data contactlessly. Such data are stored on RFID tags (electronic tags), often also transponders. The stored data are read by means of electromagnetic waves which can be coupled in via the antenna in the RFID tag and can be radiated by the antenna, respectively. The constructional size of an RFID tag is significantly determined by the antenna contained in it and thus forms a limiting factor with regard to the miniaturization of RFID tags. RFID tags known from the prior art typically have dimensions of a few millimeters to some centimeters.
RFID tags are used in electronic stock protection systems for preventing thefts, applications in automation technology (e.g. automatic identification of vehicles in traffic as part of toll systems), access control systems, cashless payment, ski passes, fuel cards, identification of animals and applications in lending libraries.
An RFID tag usually contains an antenna, a circuit for receiving and transmitting electromagnetic waves (transponder) and a signal processing circuit. Active RFID tags are battery-operated, passive RFID tags receive their energy for transmitting the information from the radio waves received.
The fact that antennas on RFID tags are usually implemented as passive components, i.e. as non-integrated circuit components, is mainly based on the fact that the energy transfer required for the communication makes (minimum) demands on the length of the antenna. Thus, for example, the radiated power of a dipole antenna decreases distinctly when the antenna becomes shorter than λ/4, λ being the wavelength of the electromagnetic radiation. As well, the smaller the dimension of the antenna, the lower the power transferred in the near field by dipole/dipole coupling in an RFID application.
Producing a non-integrated antenna separately is very expensive and in addition, further costs arise for connecting antenna to chip in a packaging process. In an RFID application, the costs for chip production, antenna production and packaging are distributed in approximately equal parts. Integrating the antenna could thus reduce the costs by at least one half.
From http://www.hitachi.com/New/cnews/030902.html, an RFID chip with an integrated antenna is known which has a dimension of 0.4 mm×0.4 mm. However, this RFID chip with integrated and thus miniaturized antenna has the disadvantage that it exhibits extremely poor coupling of the antenna to the electrical field of a readar. This leads to an extremely short range of the RFID chip with integrated antenna known from http://www.hitachi.com/New/cnews/030902.html. Although the μ chip known from http://www.hitachi.com/New/cnews/030902.html has an inbuilt antenna which, in principle, allows contactless communication, the achievable distances over which the antenna can communicate with a readar are greatly restricted due to the fact that the antenna is provided as integrated component which thus has very small dimensions. For this reason, the RFID tag known from http://www.hitachi.com/New/cnews/030902.html, due to the low power of transmitted waves, cannot be used for many RFID applications, or not with sufficiently good quality.
Araneo, R, Celozzi, S (2002) “FE Analysis of a Low-Frequency Microstrip Antenna”, IEEE Transactions on Magnetics, vol. 38, No. 2, pages 729-732 discloses a finite element analysis as a model for a macroscopic microstrip antenna with dimensions in the range of a few centimeters. For the theoretical analysis according to Araneo, R, Celozzi, S (2002) “FE Analysis of a Low-Frequency Microstrip Antenna”, IEEE Transactions on Magnetics, vol. 38, No. 2, pages 729-732, a basic plane is assumed on which a ferroelectric layer is arranged, on which a ferrimagnetic layer is arranged on which a microstrip antenna is arranged. According to Araneo, R, Celozzi, S (2002) “FE Analysis of a Low-Frequency Microstrip Antenna”, IEEE Transactions on Magnetics, vol. 38, No. 2, pages 729-732, the ferroelectric material and the ferrimagnetic material are used for lowering the resonant frequency of the antenna and thus providing an antenna for low-frequency applications.
DE 36 13 258 A1 describes a semiconductor substrate with a monolithically integrated circuit and with an antenna structure coupled to the monolithically integrated circuit.
Furthermore, in EP 0 055 324 B1, a microwave circuit on a gallium arsenide substrate is described. The microwave circuit has a phase matching network and a radio-frequency feed network and a multiplicity of circuit structures which are connected via the circuit for controlling the electrical phase shift on radio-frequency paths.
EP 0 296 838 B1 discloses a microwave transmitter and a microwave receiver with an oscillator, the microwave transmitter and the microwave receiver, respectively, having a number of IMPATT diodes as active device. Furthermore, a microstrip surface area is provided there which, in operation, acts as resonator and, at the same time, as antenna. The IMPATT diodes and the microstrip surface area are formed from the same semiconductor substrate.
Furthermore, from DE 101 18 742 A1, a microwave millimeter wave module with integrated antenna is known. A multilayer substrate of a first dielectric layer, a second dielectric layer and a third dielectric layer are formed. On the third dielectric layer, a radio-frequency circuit line and on this a semiconductor chip is produced. A slotted hole is formed on one side of the second dielectric layer and an antenna feed line on the other side. In the first dielectric layer, a number of slotted holes are formed which radiate electromagnetic waves. An organic substrate is laminated onto the multilayer substrate by means of an adhesive layer.
EP 0 743 615 B1 describes a radio frequency identification tag circuit with embedded antenna coil. The antenna coil has two windings printed on opposite sides of a substrate. The lines of the first winding and the lines of the second winding are offset from one another in order to reduce parasitic capacitances between the windings.